GEOGRAPHICAL INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2012 customers	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011 customers	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2012 customers	Mar. 31, 2011 customers	Mar. 31, 2010 customers
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers									$ 713,368	$ 683,602	$ 613,837
Net revenues from unaffiliated customers, international									307,135	283,310	235,718
Net revenues	177,584	183,236	176,948	175,600	173,077	181,585	158,255	170,685	713,368	683,602	613,837
Number of Major Customers, Ten Percent Or Greater, Net Revenues									0	0	0
Number of Major Customers, Ten Percent Or Greater, Net Accounts Receivable	0				0				0	0
Total long-Lived Assets	90,547				85,483				90,547	85,483
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers, U.S.									406,233	400,292	378,119
Long-Lived Assets in U.S.	70,808				65,899				70,808	65,899
Europe, Middle East and Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers, international									181,761	169,521	148,070
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers, international									74,249	62,697	46,494
Americas, excluding U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers, international									51,125	51,092	41,154
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets in Foreign Countries	6,728				7,293				6,728	7,293
Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets in Foreign Countries	13,011				12,291				13,011	12,291
Office and Contact Center [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers									531,709	490,472	404,397
Mobile [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers									131,825	137,530	149,756
Gaming and Computer Audio [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers									31,855	36,736	39,260
Clarity [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues from unaffiliated customers									$ 17,979	$ 18,864	$ 20,424